(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "American sumac: a valuable tanning material and dyestuff"

s 



UNITED STAT 




T OF 



BULLETIN No. 706 

Contribution from the Bureau of Chemistry 
CARL L. ALSBERG, Chief 




Washington, D. C. 



Issued July 26, 1918; Revised November 6, 1920. 



AMERICAN SUMAC: A VALUABLE TANNING 
MATERIAL AND DYESTUFF. 

JBy F. P. VEITCH, Chemist in Charge, J. S. ROGERS and R. W. FREY, Assistant 
1 1 Chemists, Leather and Paper Laboratory. 



CONTENTS. 



Page. 

tntroduction 1 

Species of American sumac 3 

iPresent methods of gathering and 

curing . 5 

innin content 8 

imac extract _. 9 



Page. 

Disposal of extracted material 10 

Causes of poor quality in sumac 11 

Cooperation for better sumac 11 

Directions for gathering and curing 12 

Buyers of sumac 12 

Summary 13 



INTRODUCTION, 

Sumac, known also as s " shumac " or " shoemake," is a wild plant 
[rich in tannin, a product of value to the tanning and dyeing indus- 
tries. Sumac grows on ^uncultivated lands in many parts of the 
[United States and is particularly abundant and accessible east of 
the Mississippi. Plentiful stands occur on cut-over land, in old 
[fields and pastures, on mountain sides, in waste places, and on the 
[edge of swamps in the Appalachian region. Immense quantities of 
this valuable tanning and dyeing material, which cost nothing to 
[raise, remain ungathered every year, and are allowed to go to waste, 
the United States imports annually more than $5,000,000* worth 
|of vegetable tanning materials. 

Although there would seem to be little excuse for such an un- 
>nomic condition, a study of the situation reveals certain obstacles 
[in the way of making use of this sumac for the purposes to which 
it is adapted. It is hoped, however, that these difficulties may be 
overcome by the manufacturers and gatherers if they have a fuller 
1 realization of the possibilities of native sumac. The domestic 

[sumac industry is well worth organization ard development as a 

__ . _ 

1 Foreign Commerce and Navigation of the United States, 1916, U. S. Department of 
>mmerce. 



3436 20 



444109 



BULLETIN 706, IT. S. DEPARTMENT OF AGRICULTURE. 



the present none too plentiful supply of tanning 
materials, 'of lessening our dependence on foreign countries, and of 

**> giva2.llie : pe3dre *in the rural districts an additional source of 
- ^ e J-rv^ ! , i. e ,r.* ." 
income. 

Sumac leaves have long been used in tanning leather and in dye- 
ing fabrics. The value of sumac for tanning depends chiefly upon 
the fact that it yields durable light-colored or white leathers, as a 
consequence of which it is employed largely in the tanning of book- 
binding, glove, and hatband leathers, and for removing darker 
colored tanning materials from the surface of bag, case, and fair 
harness leathers. Sumac-tanned leathers have been found to be 
most durable and suitable for bookbindings and other purposes, 
where the leather must last indefinitely. The greater part of the 
gathered American sumac, however, is*used in the dyeing of cotton 
goods. 

The sumac industry in the United States is of direct interest to 
the country people of certain sections. It is largely a rural industry, 
since the sumac is harvested and cured by the country people and 
is sold through country dealers for grinding or for the manufacture 
of extract. 

In recent years the quantity of sumac gathered has been much 
smaller than formerly. Cheaper materials for making light- 
colored leathers are in use, while the demands of dyers have 
not been large. American sumac, owing to careless gathering and 
curing, yields a darker colored leather than the sumac imported from 
Sicily, and, since sumac is used for tanning light-colored leathers, 
this quality renders the American product less desirable and de- 
creases the demand for it. Another reason for the small amount 
collected is that the gatherers often earned less than could be made 
at other kinds of work. 

While it is true that American sumac, if properly handled, will 
make an excellent substitute for Sicilian sumac, consumers of sumac 
must realize that the first step necessary for the production of a 
high-grade sumac similar to the foreign article is proper gathering 
and proper curing, which can be accomplished only by offering as 
an incentive a price commensurate with the labor and the quality 
of the product. The better the sumac the better should be the price. 
In this way mutual benefit will be gained and much will be done 
toward materially developing the domestic sumac industry. 

Statistics probably do not indicate accurately the quantity of 
sumac gathered in the United States, because careful records are not 
kept by gatherers and dealers of the amounts collected and used. 
The figures for domestic production given in Table 1 were compiled 
from the Census reports, and the figures for the imports from the 



AMERICAN SUMAC. 



reports on commerce and navigation of the United States, issued by 
the United States Department of Commerce. 

TABLE 1. Production of sumac in the United States. 



Yea'r. 


Sumac extract. 


Ground sumac. 


Quantity. 


Value. 


Quantity. 


Value. 


1899.. 


Pounds. 
3,349.742 
4.093,619 
3, 148, 790 
4,512,361 


$103,085 
95, 958 
107, 456 
129, 631 


Pounds. 
9,284,000 
5,061,333 


$114,660 
65, 190 


1904. 


1909 


1914 








1 



TABLE 2. Importation of sumac into the United States. 



Year. 


Sumac extract (imported 
for consumption). 


Ground sumac (general 
importation). 


Quantity. 


Value. 


Quantity. 


Value. 


1894 


Pounds. 
1. 277, 609 
1,266,542 
1,356,020 
1, 232, 830 
1,461,373 
987,348 
1,389,733 
1,270,825 
1,029,792 
727, 449 
36,003 


$54, 533 
48,399 
50,681 
54, 171 
54, 899 
36, 025 
46, 551 
44,568 
42, 973 
35,066 
4,108 


Pounds. 
8,383,570 
12.975,970 
18,604,644 
10,974,613 
13,632,861 


$192,647 
183, 136 
276,891 
293,249 
299,170 


1899 


1904 


1909 


1910." 


1911 


1912.. 


12,498,376 
14,489,776 
10,770,400 
13, 165, 182 
21,542,390 
11,637,023 
10,557,920 
9,311,055 


235, 154 
297,506 
258, 738 
323, 448 
555,276 
365, 173 
355, 192 
307,843 


1913 


1914 


1915. 


1916 


1917 


1918 


23,906 


2,116 


1919 









Information in the possession of the Bureau of Chemistry shows 
clearly that the consumption of domestic sumac during the two or 
three years prior to 1917 was more than 10,000,000 pounds annually. 
Early in 1910 domestic sumac was quoted at $55 a ton. In June, 
1920, Sicilian sumac was worth about $90 a ton at the chief Atlantic 
ports, while domestic sumac was quoted at $75 a ton. 

SPECIES OF AMERICAN SUMAC. 

Important species of sumac growing in North America are : Dwarf 
sumac (Rhus copallina L.), white sumac (Rhus glabra L.), and stag- 
horn sumac (Rhus hirta (L.) Sudw.). Other species which contain 
tannin are : Fragrant sumac (Rhus aromatica Ait.), American smoke 
tree (Rhus cotinoides Nutt.), and coral or Jamaica sumac (Rhus 
metopium L.) . Two species of sumac are poisonous, namely : Poison 
sumac, or poison elder (Rhus vernix L.), and poison or three-leaf ivy 
(Rhus radicans L.). 

DWARF SUMAC, sometimes called BLACK or MOUNTAIN SUMAC (Rhus 
copallina) . A shrub or sometimes a small tree with maximum height 



4 BULLETIN 706, U. S. DEPARTMENT OF AGRICULTURE. 

of 30 feet and trunk diameter of 10 inches. The leaflets are dark 
green, smooth on top, paler and often hairy underneath, with edges 
smooth or few-toothed toward the apex. The fruit grows in dense 
terminal clusters, is crimson in color, and is covered with fine hairs. 
The unmistakable characteristics of this species are the winged 
growth along the leaf stem between the leaflets (PI. II, A) and the 
black specks on the new stalk. Dwarf sumac grows in dry soil, and 
may be found from Maine and southern Ontario to Florida and 
Texas, and west to Minnesota and Nebraska. 

WHITE SUMAC, sometimes called SMOOTH, UPLAND, or SCARLET 
SUMAC (Rhus ylabra) . A shrub, or rarely a small tree, 2 to 20 feet 
high. The leaflets are dark green on top and whitish underneath, 
with edges sharply saw-toothed. The fruit grows in dense terminal 
clusters, and is covered with short reddish hairs. The distinguishing 
characteristics 'of this species are the smoothness of the stalks and 
leaf stems, together with a bluish white bloom, a powdery film similar 
in appearance to that found on plums, which covers the stalks and the 
under side of the leaflets (PL III). White sumac grows in dry soil 
from Nova Scotia to British Columbia, and south to Florida, Missis- 
sippi, and Arizona. 

STAGHORN SUMAC, sometimes called HAIRY SUMAC (Rhus hirta). 
A shrub, or small tree, with maximum height of 40 feet and 
trunk diameter of 9 inches. Leaflets, dark green and nearly smooth 
on top, pale, and more or less hairy underneath, with edges sharply 
saw-toothed. The fruit, which grows in dense terminal clusters, is 
thickly covered with bright-crimson hairs. The distinguishing 
characteristic of this species is the hairy growth along the stalks and 
leaf stems (PL IV) . Staghorn sumac is found in dry and rocky soils 
from Nova Scotia to Georgia, especially among the mountains, and 
as far west as southern Ontario, Minnesota, Missouri, and Mississippi. 

Since poison sumac sometimes is mistaken for the more common 
species, and its poisonous effects are usually very severe, it seems 
desirable to describe it as an aid in distinguishing poison sumac 
from the other species. 

POISON SUMAC, sometimes called POISON ELDER (Rhus vernix). 
A shrub, or small tree, with maximum height of 28 feet and trunk 
diameter of 6 inches. The leaflets are green on top and underneath, 
with edges smooth. The fruit, which grows in loose, open clusters, 
consists of smooth white or light gray berries. It should be noted 
that poison sumac differs decidedly from the important species in 
the color and cluster formation of its fruit. Furthermore, it may 
be easily distinguished from the dwarf sumac by the absence of the 
winged growth along the leaf stems, and from the white and stag- 
horn sumac by its smooth-edged leaflets (PL V). Poison sumac 
almost invariably is found in swamps. It grows from southern 



AMERICAN SUMAC. 5 

Ontario and near the eastern coast in the Eastern and Middle 
States, south to Florida, and west to Minnesota, Missouri, and 
Louisiana. 

PRESENT METHODS OF GATHERING AND CURING. 

COMMON NAMES USED BY GATHERERS. 

Sumac is commonly termed by the gatherers either "black" or 
" white." " Black " sumac refers to dwarf sumac (Rhus copallina) , 
and "white" sumac usually means white sumac (Rhus glabra), al- 
though it is believed that this term is sometimes applied also to stag- 
horn sumac (Rhus hirta). Staghorn is not so extensively gathered 
as white sumac. In some sections, as in eastern Virginia, only black 
sumac is collected, while in others, such as the western part of 
Virginia and in West Virginia, Maryland, and Pennsylvania, small 
quantities of white sumac also are gathered. 

KINDS AND CONDITION OF SUMAC DESIRED BY EXTRACT MANUFACTURERS. 

Dwarf, or black, sumac is the only variety desired by extract 
makers, other species being refused because, it is stated, they contain 
a much higher proportion of pithy, milky stalks, and yield less ex- 
tract. ' All contracts with gatherers specify that the sumac shall be 
dwarf, or black, only. The leaves and stems of the sumac alone are 
of value. The stalk is useless. While small, short new-growth stalks, 
broken off close below the leaf stem, may be accepted by the buyer, 
the chances are that they will be refused or received at a reduction in 
price. Gatherers are advised to take particular pains to see that 
their sumac contains very little stalk and no berries. Berries are of 
no value to extract makers. 

PROPER TIME TO GATHER. 

Extract makers are opposed to the early gathering of sumac, even 
though the leaves apparently are mature. They state that the leaves 
gathered in May and June are light in weight, do not yield as much 
extract, and can not be handled as well in the extracting process. 
From the viewpoint of both gatherers and extract makers, the best 
time to gather sumac is in July, August, and September. Gathering 
should not be done after frost, as the leaves then drop off readily and 
the color of the extract made from red leaves is darker and less 
desirable than that made from light-colored, well-cured leaves. 

YIELDS PER ACRE. 

While sumac is very plentiful, especially in the eastern United 
States, it rarely covers thickly an area of any extent, but, inter- 
mingled with other vegetation, grows rather scattered in patches 



6 BULLETIN 706, U. S. DEPARTMENT OF AGRICULTURE. 

along old fence rows, and on cut-over and burned-over woodland. 
Eeports have been received that in certain sections it grows thickly, 
unmixed with other growth, and in sufficient areas to permit cutting 
with a mowing machine. Several cases of clean stand have been 
reported, but they have not come directly to the attention of the 
Bureau of Chemistry. A report has been received from eastern 
Virginia of a tract of from 10 to 15 acres of burned-over and cut-over 
land from which 5 tons of dwarf sumac (leaves, leaf stems, and cur- 
rent year's stalk) were gathered. An estimate by the bureau, based 
on white sumac gathered from a plot 20 by 30 feet, gave a calculated 
yield per acre of 4,864 pounds (green weight). This would make 
about 1,600 pounds of cured sumac. 

QUANTITY A MAN CAN GATHER IN ONE DAY. 

Many factors may influence the quantity a man can gather. Some 
of these are the experience and alacrity of the gatherer, availability 
or lack of teams for hauling, growth of sumac whether dense or 
scattering species of sumac collected, and whether leaves, leaf stems, 
and stalks, or only leaves and leaf stems are gathered. The sumac 
collected by one man in one day may weigh from 150 to 600 pounds 
when dried, but averages between 200 and 300 pounds. From experi- 
ments conducted by the bureau, in which the sumac was collected 
by an experienced gatherer, it has been estimated that the following 
amounts of sumac (leaves, leaf stems, and stalk combined) can be 
gathered in one eight-hour day by an energetic man, provided the 
stand is good, so that little time is lost in going from one patch to 
another : 

Dwarf, 728 pounds green ; loss of water in curing, 54 per cent ; cured sumac, 
335 pounds. 1 

White, 1,744 pounds green ; loss of water in curing, 67 per cent ; cured suinac, 
576 pounds. 

Staghorn, 952 pounds green ; loss -of water in curing, 58 per cent ; cured sumac, 
400 pounds. 

Where the stand is scattering or the gatherer is slow, the quantity 
gathered will be less, but in no case should an able-bodied man be 
satisfied with less than 200 pounds of cured sumac (leaves and stalks) 
from his day's work. 

In those sections where black, or dwarf, sumac grows plentifully, 
exceptionally high wages can be earned, particularly by women, 
children, and the older men, by gathering sumac. Spare time during 
July and August, which usually is a comparatively inactive period 
on the farm in the sumac-growing sections, can be profitably em- 
ployed in this way. By gathering and carefully curing sumac, at $1 

1 The dwarf sumac was more scattered than the other two varieties. This may account 
for the comparatively low figures for this species. 



AMERICAN SUMAC. 



per hundred pounds, any active gatherer can make from $2 .to $3 
a day, while at $2 per hundred pounds he can earn from $4 to $6 
a day. 

GATHERING AND CURING. 

The general practice folloAved in gathering is to break or cut (only 
the black can be broken readily) the new-growth stalk just below the 
lowest leaf stem. Sumac never should be allowed to wilt in the sun 
for more than a lew hours. It should be hauled to a barn and 
spread on the clean floor in a layer from 1 to 3 feet deep, or on racks 
which permit the circulation of air underneath. The sumac must- 
be turned once or twice each day for a week, to aid in the drying 
and to prevent the leaves from molding. The brightest sumac is 
not allowed to wilt in the sun, but is spread at once on racks in 
the barn or under cover. This method aids materially in producing 
sumac of the lightest and best color. 

LOSS IN CURING AND HANDLING. 

Experienced gatherers estimate that 100 pounds of green sumac 
makes only from 40 to 50 pounds of the cured sumac. There is still 
further loss in weight between the time of purchase by the dealer 
and the time of sale, due largely to loss of moisture, still present 
because of incomplete drying, to falling of leaves, and to the re- 
moval of adhering dirt. This loss between the purchase and sale 
by the dealer varies in amount from 5 to 15 pounds, thus making a 
total loss in weight of from 60 to 75 pounds per hundred pounds 
of the original green sumac. 

Results of laboratory experiments on the curing of sumac (leaves, 
leaf stems, and stalks), given in Table 3, show losses while curing 
which agree well with those estimated by gatherers. 

TABLE 3. Loss of moisture in curing sumac (collected September 28, 1916). 



Species. 


Duration 
of drying. 


Loss of 
moisture. 


Dwarf 


Days. 
5 


Per cent. 
50.5 


White 


25 
49 

5 


53.2 
53.6 

63.9 


Staghorn 


25 
49 

5 


66.1 
66.6 

55.5 




25 
49 


57.3 

57.8 



There is reason to believe that the loss in curing on the farm is not 
so great as the loss observed in the bureau's experiments, where the 
sumac dried out very thoroughly. 



8 BULLETIN 706, U. S. DEPARTMENT OF AGRICULTURE. 

PREPARATION FOR TRANSPORTATION. 

Sumac received by the dealers from the farmers usually comes in 
bags, or is handled loose in wagonloads like hay, and in many in- 
stances may have been hauled as far as 20 miles. Many farmers pre- 
fer to deliver the sumac in wagonloads, as they claim that too much 
time is consumed by putting it up in bags. Since the sumac becomes 
very brittle when dried and the leaflets are easily broken from the 
leaf stems, much loss occurs in handling it loose, and the gatherer can 
make more by bagging his sumac, packing each bag as full as possible. 
These bags cost the dealers 8 to 9 cents each, but are usually furnished 
without cost to the gatherers. Some gatherers, after drying the 
sumac, flail off the leaves and pack them in bags for shipment. 
Seventy-five pounds should be packed into a 4-bushel bag. 

From the small dealers to the extract manufacturers the sumac is 
usually handled in bags or bales. The cost of baling is about 10 
cents per hundredweight. 

PRICES PAID GATHERERS AND DEALERS. 

During the seasons of 1918 and 1919 in eastern Virginia the 
gatherers received from $1.25 to $1.50 per 100 pounds in trade from 
the dealers. The extract manufacturers furnished bags for use in 
hauling and shipping the cured sumac. The extract makers paid 
$1.65 per 100 pounds for the bagged material, which in this region 
includes some new-groAvth stalks as well as the leaves and leaf stems. 
In 1919 in northern West Virginia and western Maryland the 
gatherers received $1.50 per hundred pounds in trade from the 
dealers. In 1920, the price rose to $2.00 per hundred pounds at the 
shipping point. 

TANNIN CONTENT. 

The leaves and leaf stems together of the three most important 
American sumacs dwarf, white, and staghorn when air-dried 
contain approximately the same quanity of tannin that is, from 20 
to 35 per cent. 1 The leaves of fragrant sumac are said to contain 13 
per cent tannin, those of American smoke-tree 21 per cent, and those 
of coral sumac 8 per cent. Usually the quantity of tannin appears 
to be somewhat greater later in the season than in June and early 
July. The leaves contain the highest percentage of tannin after 
they are fully grown and before they begin to turn yellow or red. 

Analyses made in the Leather and Paper Laboratory of the Bureau 
of Chemistry of various samples of sumac gathered in Virginia, West 
Virginia, Maryland, and Pennsylvania gave the results shown in 
Table 4. 

1 These figures apply more particularly to Virginia, West Virginia, Maryland, and 
Pennsylvania sumacs. 



Bui. 706, U. S. Dept. of Agriculture. 



PLATE I, 




GATHERING DWARF SUMAC, THE ONLY KIND 
SUMAC DEALERS WANT. 



Bui. 706, U. S. Dept. of Agriculture. 



PLATE II, 




DWARF SUMAC LEAVES AND LEAF STEMS. 

This is the only part of bush that is of value to the extract maker. The gatherer should receive 
from 35 to 45 per cent more for the leaves and leaf stems than for the leaves, leaf stems, and 
stalks. Note the peculiar growth along the leaf stems which is characteristic of dwarf sumac. 



Bui. 706, U. S. Dept. of Agriculture. 



PLATE III. 




WHITE SUMAC LEAVES AND LEAF STEMS. 



Bui. 706, U. S. Dept. of Agriculture. 



PLATE IV. 




STAGHORN SUMAC LEAVES AND LEAF STEMS. 



Bui. 706, U. S. Dept. of Agriculture. 



PLATE V. 




POISON SUMAC. 
Do NOT GATHER THIS KIND. 



AMERICAN SUMAC. 9 

TABLE 4. Tannin content of samples of dwarf, white, and staghorn sumac. 



Species. 


Tannin in leaves and leaf 
stems. 


Tannin in stalks. 


Average. 


Maxi- 
mum. 


Mini- 
mum. 


Average. 


Maxi- 
mum. 


Mini- 
mum. 


Dwarf 


Per cent. 
28.95 
25.41 
27.66 


Per cent. 
35.03 

28.08 
30.59 


Per cent. 
19.46 
21.35 
21.53 


Per cent. 
7.77 
6.84 
7.07 


Per cent. 
9.94 
7.30 
8.09 


Per cent. 
5.09 
6.19 
6.45 


White 


Staghorn 





Dwarf sumac, it will be seen, contains somewhat more tannin than 
staghorn or white sumac. This bears out in a general way the state- 
ment of buyers in eastern Virginia, though this difference is of itself 
not great enough to justify the refusal of the white. The sumac 
samples analyzed were found to average 73.3 per cent leaves and 
leaf stems and 26.7 per cent stalks. The variation, however, was 
marked, extending, in the case of the leaves and leaf stems, from 
54 to 89 per cent, and, for the stalks, from 11 to 46 per cent. The 
large proportion of stalks indicated by the percentage last given 
should never be permitted. Gatherers must break the stalk close 
up to the lowest leaf stem, and must not gather the long stalk 
bare of leaves. If the stalks are broken close to the leaf stems, the 
sumac will usually meet the buyers' demands. Dealers and extract 
makers should insist that the sumac delivered shall not have more 
than 25 per cent of stalks. 

The portions of the plant usually considered of value for tanning 
and dyeing purposes are the leaves and leaf stems, although, as 
shown in Table 4, the stalks contain from 5 to 10 per cent tannin, an 
amount entirely too large to discard after the trouble and expense 
of collecting and hauling to market has been incurred. This tannin 
should be recovered, as an extract could be made from the stalks 
and off-colored leaves that would be satisfactory for tanning and 
dyeing purposes when color is not the primary consideration. 

SUMAC EXTRACT. 

It has been the experience of sumac extract makers that sumac 
from Virginia, West Virginia, North Carolina, and western Ken- 
tucky contains the most tannin and yields more extract than that 
from the States farther north. For that reason, they prefer to buy 
their sumac from those southern States. 

Formerly the users of domestic sumac bought the leaves or ground 
sumac, which is the sumac leaf ground to a coarse powder, and made 
their own liquors for tanning or dyeing from these materials. Re- 
cently the grinding of sumac has decreased, and users have bought 
sumac extract instead. The price of domestic sumac extract, which 



10 



BULLETIN 706, U. S. DEPARTMENT OF AGRICULTURE. 



contains usually from 22 to 24 per cent of tannin and is sold on the 
basis of its strength, has increased materially in the past few years. 
For 42 extract the quoted price a pound was: In 1914, about 3| 
cents; in 1915, from 3| to 9 cerfts; in 1916, from 5J to 10 cents; in 
1917, from 4J to 5 cents ; in 1918, from 4J to 5 cents ; and in August, 
1920, from 7 to 8 cents. 

A pound of extract contains approximately the same amount of 
tannin as a pound of properly gathered and cured leaf. In making 
the extract the tannin is extracted with large quantities of water 
which must be evaporated in expensive copper pans under skilled 
supervision and at some expense for fuel. When the extract is to be 
used, as much or more water than was evaporated in making it is 
added to secure a tanning or dyeing solution of the desired strength. 
The consumer, however, often prefers to use the extract, rather than 
to make his cwn liquor from the leaf. 

DISPOSAL OF EXTRACTED MATERIAL. 

So far as can be learned, no really satisfactory method of disposing 
of the extracted leaves is in general use. The material is placed in 
large piles or ricks, or taken to fill in waste places. A small quantity 
is used on farm land as a top-dressing to be plowed under. Analyses 
of the commercially extracted material given in Table 5 show its 
fertilizing value. 

* 

TABLE 5. Fertilizing value of commercially extracted sumac leaves and leaf 

stens and stalks. 

















Aj 


h. 




Sample 
No. 


Part of plant. 


Mois- 
ture. 


Cal- 
cium 
oxid. 


Potas- 
sium 
oxid. 


phorus 
pen- 
toxid. 


Total. 


Cal- 
cium 
oxid. 


Potas- 
sium 
oxid. 


Phos- 
phorus 
pen- 
toxid. 


32479 


Leaves and leaf 
steins 


Per cent. 
5 70 


Per cent. 
1 66 


Per cent. 
11 


Per cent. 
23 


Per cent. 
5 13 


Per cent. 
32 36 


Per cent. 
2 14 


Per ctnt. 
4 48 


32482... 


.. ..do 


5.33 


1.95 


.09 


.20 


5.32 


36.65 


1.69 


3.76 


32479 


Stalks 


4.59 


1.31 


39 


15 


3 43 


38 19 


11 37 


4 37 


32482 


do 


4.59 


1.44 


.17 


.11 


3.24 


41.36 


5.24 


3.39 























Examination of a number of unextracted sumac samples gave: 
Ash, 4 to 7.5 per cent; potassium oxid, 1.18 to 2.15 per cent. Ttie 
ash of these samples contained from 25 to 30 per cent of potassium 
oxid. 

Comparison of the percentage of potassium oxid (K 2 O) in the 
original material and in the water extract, as obtained for the tannin 
analysis, shows that although the unextracted sumac contains rather 
high percentages of potassium oxid, this is almost entirely removed 
on extraction. These experiments were made on finely ground su- 



AMERICAN SUMAC. 11 

mac leaves and leaf stems, whereas in commercial practice the ex- 
traction generally is made on the imground leaves and stalks, and 
consequently is not so thorough, especially in the case of the larger 
stalks. This practice of making extraction on the unground leaves 
and stalks undoubtedly accounts for the comparatively high per- 
centages of potassium oxid in the samples of commercially extracted 
stalks, analyses of which are given in Table 5. 

Except for the organic matter which it contains, extracted sumac 
has comparatively little value for the farmer. However, in sections 
where sumac is gathered, where the land is usually deficient in or- 
ganic matter, the extracted material can be profitably hauled a mile 
or two, especially if before scattering on the land it can be mixed 
and rotted with barnyard manure. 

CAUSES OF POOR QUALITY IN SUMAC. 

Lack of care and attention to details in gathering and curing 
results in sumac of inferior quality. Undue exposure to the sun, 
any exposure to dew or rain, heating and molding in deep layers, 
arid failure to turn once a day while curing cause decided darkening 
of the leaves and materially reduce the percentage of tannin. The 
presence of stalks, red leaves, blooms, or berries in cured sumac is 
objectionable, because they produce an undesirable color on leather. 
Furthermore, since the stalks contain only about one-fourth as much 
tannin as the leaves, their presence gives the mixture a lower tannin 
content. The presence of dirt or sand in cured sumac also is ob- 
jectionable, for it increases the weight without increasing the tannin 
content, and leathers tanned with such sumac will darken because 
of the iron present. 

COOPERATION FOR BETTER SUMAC. 

One of the objects of this bulletin is to point out the necessity for 
helpful cooperation between gatherers, dealers, and extract makers, 
with a view to the production of higher grade sumac and sumac 
extracts and the payment of higher prices to the gatherers for better 
sumac. This cooperation can be successfully maintained only if it 
is mutually beneficial. The initiative and success rest with the final 
buyers, the extract makers, who, by offering a bonus for "extra" 
quality sumac, can encourage the gatherers to make special efforts 
to produce a high-grade, bright, clean product. It is suggested 
that, for the information and guidance of gatherers, dealers and 
buyers keep on hand suitable samples, one to be known as " Stand- 
ard," for which they will pay the regular price, and another as 
" Extra," for which a bonus will be paid. Sumac materially below 



12 BULLETIN 706, U. S. DEPARTMENT OF AGRICULTURE. 

" Standard " in color or quality should be bought only at a reduc- 
tion. If the directions for gathering and curing given in this 
bulletin are carefully followed, no sumac below " Standard " will 
be produced, while much of it will be of " Extra " quality. 

DIRECTIONS FOR GATHERING AND CURING. 

In order to obtain sumac of the best quality, both as to color and 
percentage of tannin, carefully follow these directions: 

Gather only dwarf, or black sumac (PL II). Break the stalk 
bearing the leaves and leaf stems just below the lowest leaf stem; 
or, better, gather only the leaves and leaf stems, throwing away all 
blooms or berries. Harvest during July, August, and Sep- 
tember. Do not collect red or yellow leaves. As soon as gathered, 
place the sumac in the shade or under a canvas cover, which permits 
the air to get to it, and prevents undue exposure to the sun. Do 
not allow it to be wet by dew or rain, and at the end of each day 
haul the gathered sumac to a barn or open shed, w r here it should 
be spread in layers not over L| feet deep upon a clean floor, or upon 
open racks which will permit ready access of air. Do not allow 
the gathered sumac to come in contact with the bare ground at any 
time, as dirt injures its quality. Turn the layers over once or twice 
daily for from one to two weeks, or until thoroughly dry. In case 
stalks have been gathered with the leaves, remove the stalks by 
flailing and forking out. The leaves thus prepared should be of 
a uniformly light-green color. Pack tightly in bags and keep in 
a well- aired, dry loft until sold. 

BUYERS OF SUMAC. 

Sumac, when properly cured, usually can be sold to merchants in 
towns or cities near the place where it has been gathered, or it can be 
sold directly to manufacturers who buy sumac for grinding or for 
the preparation of sumac extract. Before starting to gather, how- 
ever, the gatherer should have a definite understanding and contract 
with the dealer as to the quantity which he will buy from him ; the 
price which will be paid ; how the sumac is to be delivered ; arrange- 
ments for a supply of bags, if it is to be delivered in bags ; and espe- 
cially as to the extra price to be paid for exceptionally bright, well- 
cured sumac. If the names of dealers are not obtainable by inquiry 
of merchants, hide dealers, or others in near-by towns or cities, this 
information can be obtained from the various State agricultural 
experiment stations or from the Bureau of Chemistry, United States 
Department of Agriculture, Washington, D. C. 



AMERICAN SUMAC. 13 

SUMMARY. 

Imported sumac is scarce and high priced. Domestic sumac, if 
properly gathered and cured, can be largely substituted for im- 
ported, and should bring better prices than domestic sumac as now 
cured. Sumac grows wild and abundantly on uncultivated lands, 
particularly on those east of the Mississippi River. Country people, 
especially the elderly, and women and children, can earn good wages 
from July to September by gathering and curing sumac. 

Practically the only kind of sumac gathered in this country is 
dwarf, or black (Rhm copallina) . 

Before beginning to gather, consult your local merchants or State 
experiment station to ascertain the names and addresses of buyers 
of sumac and of sumac extract makers. Be sure to arrange fully 
and clearly with the dealers as to : (1) The quantity which they will 
buy from you; (2) a supply of bags; (3) the price per hundred 
pounds ; and especially (4) an extra price for well- cured sumac leaf. 

In gathering, break the stalk close up to the leaf stem and do not 
include long bare stalks. Do not gather blooms, berries, or yellow 
or red leaves. Do not allow the gathered sumac to scald in the sun 
or to become wet with either dew or rain. Cure in the barn or 
under cover on a clean floor. Turn once or twice a day until the 
sumac is thoroughly dry and crisp. Pack and ship only in full, 
tightly packed bags. Do not bale, and do not allow dirt, stones, or 
pieces of iron to get into the bags. Such practices ultimately result 
in a loss to the gatherer. 

As now prepared for the market, domestic sumac contains less 
tannin than and is greatly inferior in color to imported Sicilian sumac. 

Proper gathering and curing will greatly improve the color of the 
domestic sumac leaf. Such leaf contains from 25 to 30 per cent of 
tannin, which is practically as much as the Sicilian leaf. 

A pound of domestic sumac extract, of 42 strength and contain- 
ing from 22 to 24 per cent of tannin, was quoted in 1914 at about 
3| cents; in 1915, from 3f to 9 cents; in 1916 from 5J to 10 cents; in 
1917, from 4J to 5 cents; in August, 1918, 4| to 5 cents; and in 
August, 1920, from 7 to 8 cents. 

The development of the American sumac industry and the pro- 
duction of bright, uniformly and properly cured domestic sumac can 
be accomplished only through the earnest and whole-hearted cooper- 
ation of the extract makers, merchants, buyers, and gatherers. Ex- 
tract makers and buyers must make every effort to stimulate the 
proper gathering and curing by offering better prices and through 
careful instructions in proper methods of gathering, curing, and 
packing. The gatherers must help by following carefully the direc- 
tions set forth in this bulletin and by working harmoniously with the 
buyers. 



ADDITIONAL COPIES 

OF THIS PUBLICATION MAY BE PROCURED FROM 

THE SUPERINTENDENT OF DOCUMENTS 

GOVERNMENT PRINTING OFFICE 

WASHINGTON, D. C. 

AT 

5 CENTS PER COPY 

V 



WASHINGTON : GOVEIINMEXT PRINTING OFFICE : 1920 



444109 

3/37 



UNIVERSITY OF CALIFORNIA LIBRARY